Quantitative Analysis of Real-Time Infrared Thermography for the Assessment of Lumbar Sympathetic Blocks: A Preliminary Study

Lumbar sympathetic blocks (LSBs) are commonly performed to treat pain ailments in the lower limbs. LSBs involve injecting local anesthetic around the nerves. The injection is guided by fluoroscopy which is sometimes considered to be insufficiently accurate. The main aim was to analyze the plantar foot skin temperature data acquired while performing LSBs in patients with complex regional pain syndrome (CRPS) affecting the lower limbs. Forty-four LSBs for treating lower limb CRPS in 13 patients were assessed. Pain medicine physicians visualized the infrared thermography (IRT) video in real time and classified the performance depending on the observed thermal changes within the first 4 min. Thirty-two percent of the cases did not register temperature variations after lidocaine was injected, requiring the needle to be relocated. Differences between moments are indicated using the 95% confidence intervals of the differences (CI 95%), the Cohen effect size (ES) and the significance (p value). In successful cases, after injecting lidocaine, increases at minute 7 for the mean (CI 95% (1.4, 2.1 °C), p < 0.001 and ES = 0.5), at minute 5 for maximum temperature (CI 95% (2.3, 3.3 °C), p < 0.001 and ES = 0.6) and at minute 6 for SD (CI 95% (0.2, 0.3 °C), p < 0.001 and ES = 0.5) were observed. The results of our preliminary study showed that the measurement of skin temperature in real time by infrared thermography is valuable for assessing the success of lumbar sympathetic blocks.

Sympathetic Blocks

The autonomic nervous system (ANS) is the part of the nervous system that regulates involuntary functions. It is composed of the sympathetic and the parasympathetic nervous systems (SNS and PNS, respectively). The sympathetic nervous system, in addition to its vital role as part of the autonomic nervous system and the emergency response, is thought to be involved in numerous pathologic, painful conditions. These conditions are referred to as Sympathetically Mediated Pain (SMP). SMP is often considered a result of a vicious circle of events, which include changes in peripheral and central somatosensory processes. This assumption is based upon the observations that the pain is spatially correlated with signs of autonomic dysfunction, blocking the efferent sympathetic supply to the affected area would relieve the pain. Sympathetic blocks emerged as a way to help diagnose and treat several painful conditions, including complex regional pain syndrome (CRPS), phantom pain, neuralgias, herpes zoster, and even fibromyalgia. Additionally, sympathetic blockades have been used to improve perfusion, treat angina and malignant arrhythmias, and posttraumatic stress disorder (PTSD) symptoms. This review contains 1 table and 68 references. Key words: Sympathetic nervous system, sympathetically mediated pain, sympathetic blocks, neuropathic pain, chronic pain, stellate ganglion block, celiac plexus block, lumbar sympathetic block, superior hypogastric plexus block

Pediatric Anesthesia Procedures

Pediatric Anesthesiology Procedures is intended as a ready resource of common procedures in Pediatric Anesthesiology for both experts and novices. It will be useful to both those with extensive training and experience as well as beginners and those with distant experience or training. A wealth of knowledge in the human factors of procedure design and use has been applied throughout to ensure that desired information can be easily located, that steps are clearly identified and comprehensible, and that additional information of high relevance to procedure completion is co-located and salient. This book begins with the basics, but quickly progresses to advanced skill sets. It is divided into four parts. Part I focuses on the airway and breathing, and advances from the basics of airway management through specialty skills such as lung isolation. Part II covers vascular access, from the fundamentals of fluid management and programming several types of common pumps, to intraosseous placement. Part III examines neuraxial regional anesthesia techniques as well as sympathetic blocks performed by those with an additional fellowship in pain management. This volume concludes with Part IV on emergencies and critical conditions including cardiopulmonary resuscitation for neonates and older children, treatment of local anesthetic systemic toxicity. It also includes four chapters which detail the anesthetic management for classic neonatal surgical pathologies, such as tracheoesophageal fistula, myelomeningocele, gastroschisis/omphalocele, and congenital diaphragmatic hernia.

Pediatric Complex Regional Pain Syndrome: Stellate Ganglion and Lumbar Sympathetic Blocks

Complex regional pain syndrome (CRPS) is a chronic, localized pain condition following an injury, typically affecting a distal extremity. Although the pathophysiology of CRPS is unclear, multiple mechanisms are implicated, including peripheral and central sensitization as well as sympathetically mediated pain. Peripheral nerve blockade can treat the somatic component of CRPS pain, while sympathetic blockade may alleviate pain that is sympathetically mediated. Signs and symptoms manifest as abnormal sensory, motor, vasomotor, and sudomotor changes that are disproportionate to the inciting event. Early recognition of the signs and symptoms, followed by rapid implementation of a multidisciplinary treatment approach—including physical therapy, psychotherapy, pharmacotherapy, and sympathetic nerve blocks, is a major factor in improving outcome and preventing treatment-resistant CRPS.

Comparative study of isobaric levobupivacaine and hyperbaric bupivacaine for subarachnoid block in elective cesarean sections

Background & Objective: Hyperbaric bupivacaine 0.5% with fentanyl is often used for spinal anesthesia in lower segment cesarean section (LSCS). Its cardiotoxicity, extended sensory block and high sympathetic blocks in parturients can be disadvantageous. Levobupivacaine, an s-enantiomer of racemic bupivacaine is truly isobaric with CSF. It should be able to produce adequate sensory block with less hemodynamic changes and less cardiovascular toxicity. We aimed to evaluate the clinical efficacy of intrathecal 0.5% isobaric levobupivacaine compared to 0.5% hyperbaric bupivacaine with fentanyl 25 µg for elective LSCS.

Outcomes of Sympathetic Blocks in the Management of Complex Regional Pain Syndrome

Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Sympathetic dysfunction may be present in complex regional pain syndrome, and sympathetic blocks are routinely performed in practice. To investigate the therapeutic and predictive values of sympathetic blocks, the authors test the hypotheses that sympathetic blocks provide analgesic effects that may be associated with the temperature differences between the two extremities before and after the blocks and that the effects of sympathetic blocks may predict the success (defined as achieving more than 50% pain reduction) of spinal cord stimulation trials. Methods The authors performed a retrospective study of 318 patients who underwent sympathetic blocks in a major academic center (2009 to 2016) to assess the association between pain reduction and preprocedure temperature difference between the involved and contralateral limbs. The primary outcome was pain improvement by more than 50%, and the secondary outcome was duration of more than 50% pain reduction per patient report. The authors assessed the association between pain reduction and the success rate of spinal cord stimulation trials. Results Among the 318 patients, 255 were diagnosed with complex regional pain syndrome and others with various sympathetically related disorders. Successful pain reduction (more than 50%) was observed in 155 patients with complex regional pain syndrome (155 of 255, 61%). The majority of patients (132 of 155, 85%) experienced more than 50% pain relief for 1 to 4 weeks or longer. The degree and duration of pain relief were not associated with preprocedure temperature parameters with estimated odds ratio of 1.03 (97.5% CI, 0.95–1.11) or 1.01 (97.5% CI, 0.96–1.06) for one degree decrease (P = 0.459 or 0.809). There was no difference in the success rate of spinal cord stimulation trials between patients with or without more than 50% pain relief after sympathetic blocks (35 of 40, 88% vs. 26 of 29, 90%, P &gt; 0.990). Conclusions The authors conclude that sympathetic blocks may be therapeutic in patients with complex regional pain syndrome regardless of preprocedure limb temperatures. The effects of sympathetic blocks do not predict the success of spinal cord stimulation.